Lower body mass index is associated with orthostatic hypotension in Parkinson's disease

Lower body mass index (BMI) is associated with orthostatic hypotension (OH) in the general population, especially in the elderly; however, no studies have addressed this issue in Parkinson's disease (PD).

We investigated the results of the head-up tilt test and BMI of patients with PD, and evaluated whether BMI is related to orthostatic systolic blood pressure (SBP) change during the head-up tilt test. PD patients were divided into male and female groups, and further divided into middle-aged (age<65years) and elderly (age≥65years) subgroups in each sex.

OH was observed in 13 of 64 male and 12 of 75 female patients with PD. BMI was lower in patients with OH than in those without, in both men and women. In the elderly group, a significant correlation between BMI and orthostatic SBP change was found (men, r=0.47, p=0.006; women, r=0.43, p=0.005), and a BMI below mean-0.5 standard deviation increased OH odds (men: BMI<20.5; odds ratio, 6.79; 95% CI, 1.06-43.36; women: BMI<18.5; odds ratio, 5.11; 95% CI, 1.05-24.96).

Lower BMI is a predisposing factor of OH in elderly patients with PD.